I have about 200,000 photos in my iCloud Library and their origin, an iMac, is up to date. While my iPhone's library is always frozen, stopped, where pictures should be they are grey boxes with clouds on them, and they never download. Is there a trick for giant libraries like syncing all the photos manually from the Mac and then turning on the cloud? I just want to avoid duplicates as well. In addition, I've left the library on the iPhone in airplane mode, on a reliable WiFi connection with no other apps open and on Auto-Lock off for days and yet it still doesn't finish. Its happening on all devices. Ive wiped the phone clean in DFU mode with latest iOS installed and without restoring simply signed into the Cloud and turned on Photos, restored through Mac backup, restored through iCloud backup, turned on and off all features, nothing has worked so far. Ive also been to the Genius Bar and the told me to simply wipe it and try again, that didnt work. Happening on all devices and signed in and out before. Bottom line my 200,000 photos that are already in the cloud fail to fully download to any of my iOS devices. It's half and half. The library will begin downloading but then about a day later, it stops. I'll have to manually scroll through to force the phone to start downloading more again but it stops then as well.